The Exchange 2007 environment is using a new security certificate called a Unified Communications Certificate which doesn't work very well with legacy e-mail applications. Customers may receive the following error: "Error while checking mail for <<Dominant>>: I said: PASS And then the POP server said: -ERR Protocol error: 16"

To resolve this error, use the following steps:

a) In Eudora, click on the "File" menu at the top of the screen and select "New Text Document".b) In the New Text Document window, enter the following text: x-eudora-setting:12909=PLAINc) The text will turn blue. Double-click on the blue text.d) Click the "Set Setting" button.e) Restart the Eudora e-mail application.f) You should now be able to receive/send mail now.

Using Telnet everythings works or using a tool like email remover. So the POP3 user/password combination is working with other clients. Clients tested: telnet / outlook 2010 and E-mail remover: http://www.email-remover.com/